A disc device such as a vehicle-installed audio machine including a disc identification device in a related art has a configuration wherein the space between upper and lower fixed disc guide members 30, 31, and 32 and 33 is set to a thickness more than the thickness of one disc and less than that of two discs, thereby preventing two discs from being inserted into the device, as shown in FIGS. 28 and 29.
Patent document 1: JP-A-2001-312850 (FIG. 7, FIG. 9 (b))